CN112956111A - Electric motor of axle assembly - Google Patents

Abstract

An electric motor for use in an axle assembly. The electric motor includes a stator having a stator core and a rotor adapted to rotate about a rotor axis within the stator core. The stator includes a series of electrically conductive windings disposed about a stator core. The windings are wound in a direction substantially parallel to the rotor axis and protrude from the first and second ends of the stator core. The stator core is formed to include a plurality of longitudinal passages arranged radially about the stator core and adapted to allow cooling fluid to flow through the passages. The passages of the stator core extend longitudinally through the stator core and are positioned between the windings such that heat generated by the windings is transferred to the cooling fluid to remove heat from the windings. The electric motor also includes a metering ring coupled to the first end of the stator core and a blow-off ring coupled to the second end of the stator core. The ring is adapted to direct a cooling fluid through the passage of the stator core to remove heat from the windings generated by operation of the electric motor.

Description

Electric motor of axle assembly

Cross Reference to Related Applications

The present application claims priority from united states provisional patent application No. 62/737,510 filed on 9/27/2018, 35u.s.c. § 119 (e). The disclosure set forth in this referenced application is incorporated by reference herein in its entirety.

Background

There is an increasing demand for vehicles that produce reduced or zero emissions during operation. More and more vehicle manufacturers are turning to electric and hybrid propulsion systems to reduce vehicle emissions and improve efficiency. These electric propulsion systems typically utilize one or more axle assemblies driven by electric machines (e.g., electric motors) to provide power to the wheels. To improve packaging of the various vehicle types and facilitate simplified assembly, the electric motor may be integrated with the axle assembly.

Accordingly, it is desirable to provide an electric motor that is capable of operating under the conditions occurring within the axle assembly while optimizing efficiency, performance, and cost.

Disclosure of Invention

According to the present disclosure, an electric motor is used with an axle assembly.

In an illustrative embodiment, an electric motor for an axle assembly includes a stator having a stator core (iron core) and a rotor adapted to rotate about a rotor axis within the stator core. The stator includes a series of electrically conductive windings disposed about a stator core. The windings are wound around the stator core in a direction substantially parallel to the rotor axis.

In the illustrative embodiment, the stator core is formed to include a plurality of longitudinal passages arranged radially around the stator core and adapted to allow cooling fluid to flow through the passages. The passages of the stator core extend longitudinally through the stator core and between the windings such that heat generated by the windings is transferred to the cooling fluid to remove heat from the windings.

In an illustrative embodiment, the motor further includes a metering ring coupled to the first end of the stator core and a discharge ring coupled to the second end of the stator core. The rings are adapted to direct a cooling fluid through the passages of the stator core to remove heat from the windings generated by operation of the electric motor.

Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of exemplary embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.

Drawings

Other advantages of the present invention will become readily apparent as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

FIG. 1 is a perspective view of a first axle assembly according to an embodiment of the present invention.

FIG. 2 is a perspective view of the first axle assembly shown in FIG. 1 with a cover removed to show the gear train and the electric motor and cooling system of the present invention.

FIG. 3 is a perspective view of the axle assembly shown in FIG. 2 with the housing removed to show the gear train and the electric motor and cooling system of the present invention.

FIG. 4 is a perspective view of a second axle assembly in accordance with an embodiment of the present invention.

FIG. 5 is another perspective view of the axle assembly shown in FIG. 4.

FIG. 6 is a perspective view of the axle assembly shown in FIG. 4 with the housing removed to show the gear train and the two electric motors and cooling system of the present invention.

FIG. 7 is a perspective view of the gear train, electric motor and cooling system of the first axle assembly of the present invention.

Fig. 8 is another perspective view of the electric motor and cooling system shown in fig. 7.

Fig. 9 is a rear perspective view of an electric motor including a stator, with the stator shown partially transparent.

Fig. 10 is a cross-sectional front perspective view of the electric motor and stator shown in fig. 9.

Fig. 11 is a partial perspective view of the electric motor and stator of fig. 9 taken through a slot defined in the stator.

FIG. 12 is a partial cross-sectional view of the electric motor and stator of FIG. 9 taken through the fastener.

Fig. 13 is another cross-sectional front perspective view of the electric motor and stator shown in fig. 9.

Fig. 14 is a cross-sectional view of the electric motor and stator of fig. 9 disposed in a housing.

Fig. 15 is another cross-sectional view of the electric motor and stator disposed in the housing of fig. 14.

Fig. 16 is a front perspective view of an electric motor including a stator and a rotor.

Fig. 17 is an enlarged front perspective view of the stator and rotor of fig. 16 showing slots defined in the stator.

FIG. 18A is a schematic view of the cooling system of the present invention.

Fig. 18B is a graph of slots defined in a stator and a graph of flow through the slots.

FIG. 19 is a perspective view of the clamp ring, metering ring and drain ring.

Fig. 20 is another perspective view of the gripper ring and metering ring of fig. 19.

Fig. 21 is another perspective view of the metering ring of fig. 20.

Fig. 22 is an enlarged perspective view of the metering ring of fig. 20.

Fig. 23 is a perspective view of the blow-off ring of fig. 19.

Fig. 24 is a perspective view of the rotor shown in fig. 16.

Fig. 25 is an enlarged perspective view of the electric motor and the rotor.

Fig. 26 is a perspective view of the electric motor assembly.

Fig. 27 is a cross-sectional view taken along line 27-27 of fig. 26.

Fig. 28 is an enlarged view of fig. 27.

Fig. 29 is a cross-sectional view taken along line 29-29 of fig. 26.

Fig. 30 is a cross-sectional view taken along line 30-30 of fig. 26.

FIG. 31 is a cross-sectional view taken along line 31-31 of FIG. 26

Detailed Description

Referring to the drawings, wherein like reference numbers refer to like components throughout the several views, the present invention includes anelectric axle assembly 100 for a vehicle, such as a frame truck. In the illustrated embodiment, wheels are disposed at opposite ends ofelectric axle assembly 100 to support the vehicle for transport along the ground.Electric axle assembly 100 propels the vehicle by transmitting power to the wheels to rotate the wheels along the ground.

Theelectric axle assembly 100 includes ahousing 104 supporting anelectric motor 106 and agear train 108, as shown in fig. 1 and 3. Anelectric motor 106 is coupled to thehousing 104 and engages with agear train 108 to transfer power to the wheels. Thegear train 108 generally includes a series of gears and shafts rotatably supported within thehousing 104.Electric axle assembly 100 may also include two wheel ends coupled tohousing 104.

Theelectric motor 106 includes astator 116 having a stator core (iron core) 120 and arotor 114 adapted to rotate about a rotor axis within thestator core 120, as shown in fig. 3 and 8.Stator core 120 includes a series of electricallyconductive windings 122 disposed aboutstator core 120. Thewindings 122 are wound in a direction substantially parallel to the rotor axis. Thestator core 120 is formed to include a plurality oflongitudinal passages 124, thelongitudinal passages 124 being arranged radially around thestator core 120 and adapted to allow cooling oil to flow through thepassages 124, as shown in fig. 9 and 17.Passages 124 ofstator core 120 extend longitudinally throughstator core 120 and betweenwindings 122 such that heat generated by the windings is transferred to the cooling oil to remove heat fromwindings 122. The motor also includes ametering ring 158 coupled to a first end of thestator core 120 and a blow-off ring 170 coupled to a second end of thestator core 120, as shown in fig. 19 and 28. Therings 158, 170 are adapted to direct cooling oil through thepassages 124 of thestator core 120 to remove heat from the windings generated by operation of theelectric motor 106.

A firstelectric axle assembly 100 is shown in fig. 1-3, theelectric axle assembly 100 shown herein being configured for use with a low-chassis bus and including twohousings 104, wherein eachhousing 104 is disposed on an opposite side of theelectric axle assembly 100 and has ahousing shell 138 and acover 140, as shown, for example, in fig. 2. Eachhousing 104 is configured to include anelectric motor 106 such that the wheels on each side of the axle are driven by aseparate motor 106. In a second embodiment, such as shown in fig. 4-6, theelectric axle assembly 1100 includes asingle housing 1104 configured to house and support twoelectric motors 106.

A secondelectric axle assembly 1100 is shown in fig. 4-6. The secondelectric axle assembly 1100 is similar to the firstelectric axle assembly 100 described above in connection with fig. 1-3. Thus, the components and structural features of the secondelectric axle assembly 1100 that correspond to the firstelectric axle assembly 100 are provided with the same reference numerals increased by 1000. Herein, the above description of the firstelectric axle assembly 100 may be incorporated by reference with respect to the secondelectric axle assembly 1100 without limitation, unless otherwise specified.

Referring to fig. 1-3, thehousing 104 includes ahousing shell 138 and acover 140. Thehousing shell 138 is formed to include the interior 112 enclosed by thecover 140 and includes theelectric motor 106 and thegear train 108. As shown in fig. 8, theelectric motor 106 includes arotor 114 and astator 116. Therotor 114 is supported for rotation about a rotor axis 118 by the bearing 110 in thehousing 104. Astator 116 is secured to thehousing 104 and is disposed about therotor 114 such that therotor 114 rotates within thestator 116.

Thehousing 104 of theaxle assembly 100 includes asump 150 within thehousing 104 to collect and store lubricating oil (shown in FIG. 2), which is also used for cooling purposes. Portions of thegear train 108 may extend partially into thesump 150, thereby allowing oil to contact and spread into the gears of thegear train 108. Splash lubrication may be used to lubricate thegear train 108. The rotation of the gears causes oil to splash throughout theinterior 112 of thehousing 104, thereby lubricating the contact surfaces. The splashed oil will drain back into thesump 150 where it is cooled and degassed.

4-6,housing 1104 includes ahousing body 1138 and acover 1140. Thehousing case 1138 is formed to include an interior 1112, the interior 1112 being enclosed by acover 1140, and theelectric motor 106 and the gear train 1108 being disposed therein. Thehousing 1104 includes asump 1150 for collecting and storing lubricating oil.

During operation, theelectric axle assembly 100, 1100 generates heat primarily through friction between contacting surfaces and current flowing through theelectric motor 106. The performance of theelectric motor 106 may be improved by transferring heat away from theelectric motor 106 during operation using acooling system 144 to prevent excessive heat from accumulating in theelectric motor 106, as shown in fig. 7. Thecooling system 144 includes lubricating oil used as a coolant, apump 146, and aheat exchanger 148, as shown in fig. 3. Generally, thecooling system 144 reduces the temperature of theelectric axle assembly 100 by pumping a coolant fluid through theheat exchanger 148 prior to distributing the coolant fluid to theinterior 112 of thehousing 104, 1104.

In order to bring the coolant fluid into close contact with theelectric motor 106, the oil used to lubricate theelectric axle assembly 100 also serves as a coolant. Oil is pumped through thecooling system 144 and supplied to theelectric motor 106 and the contacting surfaces of thegear train 108, as shown in fig. 3. As such, thepump 146 is an oil pump that pumps oil through thecooling system 144, theheat exchanger 148, and the oil supply lines to direct the oil to the desired components within theinterior 112 of thehousing 104. Theoil pump 146 may be powered by a separate electric motor or may be driven by thegear train 108. In some embodiments (not shown), the cooling system may include twopumps 146, where each pump is powered by a respective electric motor.

Referring now to fig. 7, wherein theelectric motor 106 is shown coupled to thegear train 108 of the firstelectric axle assembly 100. Theclamp ring 136 is disposed between thefastener 142 and thestator 116 at one end of theelectric motor 106. Theclamp ring 136 evenly distributes the clamping force from thefasteners 142 across thestator 116 to couple theelectric motor 106 to thehousing 104. Theclamp ring 136 is formed to include aclamp ring gallery 192 to direct oil through theelectric motor 106.

Therotor 114 of theelectric motor 106 includes arotor shaft 126 and a rotor core (iron core) 128 coupled to therotor shaft 126, as shown in fig. 13. A plurality ofmagnets 130 are disposed inrotor core 128 and arranged radially aboutrotor shaft 126, as shown in fig. 14. Therotor shaft 126 is formed to include abore 132 extending therethrough. Adrive shaft gear 134 is coupled to one end of therotor shaft 126 to engage thegear train 108.

Thestator 116 of theelectric motor 106 includes astator core 120 andwindings 122. Thestator core 116 has a generally circular profile extending from afirst end 116A to asecond end 116B.Windings 122 are electrical conductors, such as copper wires, that are radially disposed aboutstator core 120 and receive electricity to generate a magnetic field for rotating (or braking)rotor 114.Windings 122 are wound in a direction generally parallel to rotor axis 118 and protrude from bothfirst end 116A andsecond end 116B.

Thestator core 120 is formed to include a plurality of cooling slots orpassages 124 arranged radially around thestator core 120, as shown in fig. 9. Thepassageway 124 extends longitudinally through thestator core 120 from a slot inlet 124I to a slot outlet 124O. Thepassages 124 are arranged such that they are spaced apart between thewindings 122. Thepassage 124 has a generally elliptical cross-section when viewed from the end, as shown in fig. 17, however thepassage 124 may have varying degrees of curvature or may be circular. Further, thepassages 124 may extend parallel to each other in the axial direction, or may form a spiral shape around thestator core 120.

Fig. 10 and 11 show cross-sectional views of thestator 116 and theclamping ring 136 of theelectric motor 106. One of thepassages 124 can be seen spaced from thewindings 122 and in fluid communication with theclamp ring gallery 192 to allow fluid of thepassage 124 to enter theclamp ring 136. As best shown in fig. 16 and 17, thefirst end 116A of thestator 116 is exposed to show the passage inlets 124I arranged radially around thestator core 120 in an alternating manner with thewindings 122 positioned within thechannels 123. This arrangement allows the cooling oil to be positioned adjacent and parallel to the windings so that heat can be effectively removed from thestator 116.

As shown in fig. 19 and 20, theclamp ring 136 includes anupper portion 198 and alower portion 200 that interlock to form a ring. Although a two-piece retaining ring is shown, the retainingring 136 may also be a one-piece unit. Eachportion 198, 200 is formed to include a plurality ofopenings 202 that receive the threadedfasteners 142 for coupling theelectric motor 106 to thehousing 104. In one embodiment, theclamp ring 136 is formed from a polymer or composite material, such as by an injection molding process. In another embodiment, theclamp ring 136 is formed from a fiber reinforced polymer such as glass filled nylon.

Eachopening 202 includes aninsert 204, theinsert 204 preventing theclamp ring 136 from deforming when the threadedfastener 142 is tightened. Theinsert 204 may be formed of a metal (e.g., steel or aluminum) capable of withstanding the compressive forces of thefastener 142. Theinsert 204 may be secured to eachopening 202 by pressing or insert molding.

Theclamp ring 136 is formed to include aclamp ring gallery 192, theclamp ring gallery 192 conveying oil from the clamp ring gallery inlet 192I through theclamp ring 136 to one or more clamp ring gallery outlets 192O for further distribution within theinterior 112 of thehousing 104, as shown in fig. 11. Theclamp ring gallery 192 may be formed as a cavity in a molding process by an insert molding process or by a machining operation.

As shown in fig. 7 and 8, oil stored in asump 150 of eachhousing shell 138 supplies thepump 146 via apickup tube 152 in fluid communication with the inlet 146I of thepump 146, as shown in fig. 2. The pick-uptube 152 may include a pick-upscreen 154 or filter element to help prevent contaminants that have settled in thesump 150 from reaching thepump 146. Oil fromsump 150 flows through eachpickup tube 152 and intopump 146, and pump 146 pumps the oil into amain line 156 coupled to pump outlet 146O, as shown in FIG. 3.Main line 156 is coupled between pump outlet 146O andheat exchanger 148.

In one embodiment, thecooling system 144 includes asingle heat exchanger 148, theheat exchanger 148 cooling the oil received from bothhousings 104 by transferring heat into the second coolant fluid. Aheat exchanger 148 is disposed downstream of thepump 146 and removes heat from the oil. The second coolant fluid is part of a second cooling system that is used in the vehicle to cool other vehicle components, such as the battery and/or the power inverter. In some embodiments, more than oneheat exchanger 148 may be implemented, for example, in an axle having twoindependent cooling systems 144, to increase the cooling capacity of thecooling systems 144. Theheat exchanger 148 may use a variety of fluids (e.g., water or antifreeze) as the second coolant fluid. Theheat exchanger 148 may be further configured as a radiator to cool the oil with a source of flowing air. Furthermore, the heat rejection requirements of theheat exchanger 148 may allow the use of a finned oil tank to cool the oil without airflow. Still further, it is contemplated that coolingsystem 144 may include a thermostat (not shown) disposed betweenoil pump 146 andheat exchanger 148 that prevents oil from flowing intoheat exchanger 148 until a predetermined temperature is reached to help maintainaxle assembly 100 at an optimal operating temperature.

The cooling oil from theheat exchanger 148 flows into ashell housing gallery 184 defined in theshell housing 138 of theshell 104, as shown in fig. 14. Thehousing shell gallery 184 may include one or more passages formed in thehousing shell 138 by casting or by machining. Each passage conveys oil from the shell housing gallery inlet 184I to one or more shell housing gallery outlets 184O for further distribution into theinterior 112 of theshell 104.

Fig. 14 shows a cross-sectional view of theshell housing 138 taken through one of theshell housing galleries 184. Theshell housing gallery 184 conveys oil from the shell housing gallery inlet 184I to the components of the cooling system coupled with the shell housing gallery outlet 184O. Thecooling system 144 includes ajumper 190 component that conveys oil from theshell housing gallery 184 to theclamp ring gallery 192. Thejumper tube 190 extends between a first end coupled to theshell housing 138 and in fluid communication with the shell housing gallery outlet 184O and a second end coupled to theclamp ring 136 and in fluid communication with theclamp ring gallery 192. Oil flows from one of the shell housing gallery outlets 184O through thejumper tube 190 into theclamp ring gallery 192. It is contemplated that oil may be delivered to theclamp ring gallery 192 in alternative and additional ways. For example, thehousing shell gallery 184 may be omitted and oil delivered from thepump 146 directly to theclamp ring gallery 192. Similarly, a cover gallery (not shown) may be defined in thecover 140 and fluidly communicate with theclamp ring gallery 192 to supply oil to theelectric motor 106.

Also shown in fig. 14 is adeconstitcher cap 236, which deconstitchercap 236 may be coupled to thehousing shell 138. In this embodiment, thedisintegrator lid 236 is formed to include adisintegrator lid gallery 238 and abore spray 240. Theresolver lid gallery 238 is in fluid communication with one of the housing shell gallery outlets 184O and receives oil to supply thebore spray head 240. Theresolver cover 236 protrudes through theouter housing 138 into thebore 132 of therotor 114, with abore spray 240 extending into thebore 132. Theorifice spray 240 supplies oil into theorifices 132 to cool therotor 114 as therotor 114 rotates within thestator 116.

Thelip 242 is disposed in thebore 132 opposite thebore spray tip 240 and blocks oil that has been sprayed into thebore 132 from flowing back into thesump 150. Thelip ring 242 prevents oil from draining back too quickly into thesump 150, thereby increasing the time that the oil is in contact with therotor 114 to remove additional heat. Once sufficient oil has been injected into thebore 132, the oil flows past thelip 242, out of thedrive shaft gear 134 and back to thesump 150. Further,several feed holes 244 may be defined through therotor shaft 126 and into thebore 132. The feed holes 244 provide a path for oil to flow from thebore 132 into thebearing 110. As therotor 114 rotates, oil is forced through the feed holes 244 into thebearing 110, thereby reducing friction and heat.

Thecooling system 144 also includes a windingspray 194, the windingspray 194 being disposed above thewindings 122 of theelectric motor 106 and coupled to theclamp ring 136 in fluid communication with one of the clamp ring gallery outlets 192O, as shown in fig. 11 and 20. The windingspray 194 is an elongated tube having a shaped portion that provides clearance between the windingspray 194 and thewindings 122 of theelectric motor 106. The windingspray head 194 includes a series of outlet holes 195 that direct oil onto thewindings 122. The oil flows from the clamp ring gallery outlet 192O, through the windingspray head 194, and to a series of outlet holes 195, as shown in FIG. 19.

As shown in fig. 19-22, theelectric motor 106 includes ametering ring 158 to direct the oil flow into thestator 116 to further cool theelectric motor 106. In one embodiment,metering ring 158 is formed to include: anannular body 160 and acoolant passage 162 formed in themetering ring 158.Metering ring 158 directs oil intostator 116 to coolstator core 120 andwindings 122 viacoolant passages 124, as shown in fig. 17.Metering ring 158 is formed from a polymeric material and is coupled tofirst end 116A ofstator 116 usingclamp ring 136 andfasteners 142. Thecoolant passages 162 face thestator core 120 and include one or more inlets 162I disposed about theannular body 160 that receive oil from theclamp ring gallery 192, as shown in fig. 22. Themetering ring 158 also includes a plurality offingers 164, thefingers 164 being disposed radially about theannular body 160 and extending radially inward toward the rotor axis 118. Thefingers 164 correspond to thepassages 124 in thestator core 120 such that eachfinger 164 overlaps a respective passage inlet 124I. Eachfinger 164 is formed to include afinger channel 166 in fluid communication with therespective slot 124 andcoolant channel 162 such that oil flows from the coolant channel inlet 162I through thefinger channel 166 and to eachpassage 124. The arrangement of thefingers 164 may be different than that shown, and alternatively, themetering ring 158 may be configured such that oil flows directly from thecoolant channels 162 into thestator 116 without thefingers 164.

Eachfinger passage 166 allows oil to flow into thepassage 124 through the slot inlet 124I at a predetermined rate, as shown in fig. 17 and 22. In order to provide uniform and even cooling of thestator 116 by the oil flowing into eachpassage 124, eachfinger passage 166 may define an outlet area 168 corresponding to an unobstructed area (region) of the respective inlet 124I.Finger passages 166 having relatively larger exit areas 168 allow more oil to flow into therespective slots 124 thanfinger passages 166 having relatively smaller exit areas 168.

When oil flows into thecoolant passage 162 and around thering body 160, the pressure of the oil decreases with distance from the coolant passage inlet 162I, as shown in fig. 22. The pressure of the oil in thecoolant passage 162 is greatest at thecoolant passage inlet 162. The pressure supplied to eachfinger passage 166 affects the flow of oil into each slot inlet 124I, i.e., the rate of oil flow through a given area will increase with increasing pressure. To uniformly cool theelectric motor 106, the finger passage outlet areas 168 vary as a function of the distance from the coolant passage inlets 162I to therespective fingers 164.

Referring particularly to FIG. 22, there is shown a portion ofmetering ring 158 and a number offingers 164A, 164B, 164C … 164F, each having arespective finger channel 166A, 166B, 166C … 166F, according to one embodiment. Here, thefingers 164F are arranged farther from the coolant channel inlet 162I than the fingers 164A, and therefore, the pressure of the oil at thefinger channels 166F is less than the pressure at thefinger channels 166A. To even the flow intopassage 124, finger passage outlet area 168F offinger passage 166F is smaller than fingerpassage outlet area 168A offinger passage 166A. Thefingers 164 may be further configured to supply oil to thepassage 124 at a rate different than that described above. For example, regardless of the distance between the coolant channel inlets 162I and therespective fingers 164, additional oil may be directed to portions of thestator core 120 corresponding to localized areas of increased heat.

The oil flowing into thepassage 124 is heated by thestator 116 and discharged through the slot outlet 124O at the opposite end of thestator core 120, as shown in fig. 14 and 23. Theelectric motor 106 includes a blow-off ring 170, the blow-off ring 170 disposed about the rotor axis 118 and coupled to thesecond end 116B of thestator 116 through the use of theclamp ring 136. The blow-off ring 170 includes anannular body 172, theannular body 172 being formed to include acollection channel 174 on a side of theannular body 172 facing thestator core 120. The blow-off ring 170 also includes a plurality offingers 176 disposed radially about theannular body 172 and extending toward the rotor axis 118. Eachfinger 176 corresponds to one of thepassages 124 in thestator core 120 such that eachfinger 176 is adjacent one of the slot outlets 124O, which is similar in arrangement to themetering ring 158. Eachfinger 176 is formed to include afinger channel 178 in fluid communication with therespective groove 124 andcollection channel 174 such that oil flows from eachpassage 124 out of the respective groove outlet 124O, into therespective finger channel 178, and to thecollection channel 174. The blow-off ring 170 may be formed from a polymeric material or an elastomeric material such as rubber.

Fig. 18A and 18B illustrate an exemplary configuration of thecooling system 144 and the effect of oil flowing through thepassages 124 in thestator core 120. Specifically, fig. 18A is a schematic view ofcooling system 144, which showspassages 124 arranged aroundstator core 120. The oil flow from thehousing shell gallery 184 supplies aclamp ring gallery 192, which clampring gallery 192 supplies oil to themetering ring 158. Fig. 18B shows a graph of the flow rate (flow velocity) through each cooling passage (groove) 124. FIG. 18B also shows a comparison of flow throughpassage 124 betweenmetering ring 158 that adds no restriction (baseline) 232 tofinger passage 166 andmetering ring 158 that addsrestriction 234 tofinger passage 166. These restrictions equalize (homogenize) the flow into eachslot 124 around thestator 116.

As shown in fig. 19 and 23, thedrain ring 170 directs oil from thepassage 124 to thesump 150 where the oil will collect for recirculation through thecooling system 144. To direct oil to thesump 150, thedrain ring 170 is formed to include anoil drain 180. Anoil drain groove 180 is in fluid communication with thecollection channel 174 and is disposed near a lower portion of thedrain ring 170. Gravity draws oil from the upper portion of thecollection channel 174 to the lower portion where it will pass through theoil drainage groove 180 into theoil sump 150.

Referring specifically to fig. 23, a blow-off ring 170 is shown according to one embodiment, along with a number of fingers 176A, 176B, 176C, each having a respective finger passage 178A, 178B, 178C. Oil flows from thepassages 124 into therespective finger channels 178 and into thecollection channel 174. Gravity and pressure cause the oil to flow from thecollection channel 174 toward theoil drain 180 and into theoil sump 150.

Fig. 26 shows cooling oil entering thejumper tube 190, as indicated byarrows 300, reaching theclamp ring gallery 192 and entering thepassage 124 of thestator core 120 from theclamp ring gallery 192 and themetering ring 158. The oil passes through thepassages 124 around thestator core 120 to thedrain ring 170 where the oil returns to the oil sump of thehousing 104, as shown in fig. 27 and 28. The cooling oil enters theclamp ring gallery 192 and themetering ring 158 and enters thepassages 124 between thewindings 122 as indicated byarrows 302 in fig. 29 and 30.Rotor 114 includesimpeller blades 304 adapted to direct cooling oil radially outward, as indicated byarrows 306 in FIG. 30. Fig. 31 shows that oil exits frompassage 124 and entersdrain ring 170, as indicated byarrow 308. Oil enters therotor 124 as indicated byarrow 310 and exits throughopening 312 as indicated byarrow 314.

Fig. 24 and 25 arerotor shafts 126 for theelectric motor 106. As described above, thedrive shaft gear 134, which is in mesh with thegear train 108, is coupled to therotor shaft 126. In this embodiment, thedrive shaft gear 134 is integrally formed on therotor shaft 126, which improves the strength and durability of therotor shaft 126. Thedrive shaft gear 134 is formed to include a plurality ofbalance holes 224 arranged radially about the rotor axis 118. The balancing holes 224 allow therotor 114 to be balanced during manufacturing to reduce unwanted vibrations during operation. The balance holes 224 receivebalance weights 226 as needed to distribute weight about the rotor axis 118. Fig. 25shows balancing weights 226 in several balancing holes 224. Eachbalance weight 226 may have a different weight to correct for minor variations in the manufacturing process. More orfewer balance weights 226 than shown in fig. 25 may be used, including zerobalance weights 226. Thebalance weight 226 may be coupled to thedrive shaft gear 134 by welding, pressing, peening, threading, or the like.

Typically, a vehicle includes a chassis on which a body and other equipment may be supported. For example, a cab, cargo box, boom or hook system may be mounted to the chassis. The chassis includes a frame rail; suspension components such as springs, shock absorbers, and trailing arms; and brake components such as cylinders, calipers, brake rotors, brake drums, brake hoses, and the like.Electric axle assembly 100 is generally mounted perpendicular to the frame rails so that the vehicle travels in a direction aligned with the frame rails. Thus, anaxle centerline axis 102 is defined through theelectric axle assembly 100, and theaxle centerline axis 102 extends outwardly from the side of the vehicle.

Electric axle assembly 100 may be configured for both "single-wheel" and "two-wheel" applications. In a "single wheel" application, one wheel is coupled at each end ofelectric axle assembly 100. Similarly, in a "two-wheeled" application, pairs of wheels are disposed at each end ofelectric axle assembly 100. Vehicles that require increased payload and tractive capacity are one example of a "two-wheeled" application. Vehicles requiring further increases in payload/tractive capacity may be equipped with two or moreelectric axle assemblies 100. Some vehicles may require drive means other than wheels. For example, tracks or rail wheels may be coupled toelectric axle assembly 100 to propel the vehicle over loose terrain and along a railroad, respectively.Electric axle assembly 100 may be mounted to a vehicle at both the front and rear to enable a variety of drive types, such as front-wheel drive, rear-wheel drive, and full/four-wheel drive.

Vehicle performance is optimized when contact between the wheel and the ground is uninterrupted on various surfaces. To more easily follow the ground, the suspension system movably coupleselectric axle assembly 100 to the frame rails. The suspension system allowselectric axle assembly 100 to move relative to the frame rails and push the wheels toward the ground when the vehicle encounters a ground defect. The suspension system may include: springs and dampers that absorb motion and improve ride quality; a control arm that constrains movement ofelectric axle assembly 100; and other elements depending on the application, such as steering and kinematic links.Electric axle assembly 100 may also be installed on vehicles that were not originally equipped withelectric axle assembly 100.Electric axle assembly 100 can be retrofitted to these vehicles to provide electric drive train upgrades.

Electric axle assembly 100 can be used in hybrid vehicles and all-electric vehicles. In an all-electric vehicle, the power used to powerelectric axle assembly 100 may be stored in a battery mounted on the chassis. Alternatively, power may be supplied from an external power source, such as an overhead line or a third rail system. If the vehicle is configured as a hybrid vehicle, an internal combustion engine may be mounted to the chassis and coupled to an electric motor capable of generating electrical power, which may be directly powering theelectric axle assembly 100 or stored in a battery.

It should be understood that theelectric motor 106 may be interchangeably used with either of theelectric axle assemblies 100, 1100. Theelectric motor 106 may be coupled to thehousing 104, 1104 using threadedfasteners 142 that extend through thestator 116 and into thehousing shell 138, 1138.

Fig. 12 shows a cross-sectional view of theelectric motor 106 taken along a plane that intersects one of theelongated fasteners 142. Here, thestator core 120, therotor core 128, and the winding 122 are cut by the plane. To effectively package theelectric motor 106, reduce complexity during assembly and provide the necessary clearance between the rotating components, the shape of thewindings 122 at thefirst end 116A of thestator 116 is different than the shape at thesecond end 116B of thestator 116. Specifically, the winding has afirst end 122A and asecond end 122B, wherein thefirst end 122A has a different profile and orientation than thesecond end 122B. More specifically,first end 122A is spaced afirst distance 228 from an exterior ofstator core 120 andsecond end 122B is spaced asecond distance 230 from the exterior ofstator core 120. Here, thefirst end 122A and thesecond end 122B of the winding 122 are each formed in a coil shape, with thesecond end 122B being formed closer to the rotor axis 118 than thefirst end 122A. By increasingsecond distance 230 betweensecond end 122B and the exterior ofstator core 120,fasteners 142 may be disposed closer to rotor axis 118 to allow the size ofstator 116 to be maximized.

In the embodiment shown throughout the figures, thefastener 142 includes anelongated stud 210 andnut 212, thestud 210 andnut 212 being disposed radially about the rotor axis 118 to couple theelectric motor 106 to thehousing 104. Thestuds 210 are screwed into thehousing shell 138 and extend through thestator 116 so as to project from theclamping ring 136 in the direction of thecover 140. Anut 212 is threaded onto thestud 210 to clamp theelectric motor 106 and theclamp ring 136 to thehousing shell 138. Due to the configuration of thewindings 122, the use of thestud 210 andnut 212 allows the size of the electric motor to be further optimized by placing thefastener 142 closer to the rotor axis 118 than would otherwise be the case.

As described above,electric axle assemblies 100, 1100 transmit torque and power to the wheels usinggear trains 108, 1108. Generally, thebearings 110 are used to reduce friction between the rotating components of thegear trains 108, 1108. Various types ofbearings 110 may be used, such as journal (slide) bearings, roller bearings, ball bearings, etc., depending on the requirements of the application. By using a lubricant (e.g. oil) the friction can be further reduced. Oil is supplied to the contact surfaces between components, such as gear teeth andbearings 110, to reduce wear and heat caused by motion within thegear train 108, 1108.

While various features of the invention have been particularly shown and described with reference to illustrative embodiments thereof, it must be understood, however, that these specific arrangements are merely illustrative and that the invention is to be given its fullest interpretation within the scope of the appended claims.

Claims (20)

Translated fromChinese

1.用于车桥组件的电动马达，所述电动马达包括：1. An electric motor for an axle assembly, the electric motor comprising:具有定子芯的定子，以及适于在所述定子芯内围绕转子轴线旋转的转子；a stator having a stator core, and a rotor adapted to rotate within said stator core about a rotor axis;与所述转子相关联并围绕所述转子定位的多个磁体，所述磁体适于随着所述转子旋转；a plurality of magnets associated with and positioned about the rotor, the magnets adapted to rotate with the rotor;围绕所述定子芯设置的多个导电绕组，所述绕组沿着大体上平行于所述转子轴线的方向缠绕，并且从所述定子芯的第一端和第二端突出；并且a plurality of conductive windings disposed around the stator core, the windings being wound in a direction substantially parallel to the rotor axis and protruding from first and second ends of the stator core; and所述定子芯被形成为包括多个纵向通路，所述通路径向围绕所述定子芯布置并且适于允许冷却流体流过所述通路，所述通路纵向延伸穿过所述定子芯并且定位于所述绕组之间，以使得由所述绕组产生的热量被传递至所述冷却流体，以便从所述绕组中去除热量。The stator core is formed to include a plurality of longitudinal passages arranged radially around the stator core and adapted to allow cooling fluid to flow therethrough, the passages extending longitudinally through the stator core and positioned at the stator core. between the windings so that heat generated by the windings is transferred to the cooling fluid for removing heat from the windings.2.根据权利要求1所述的电动马达，所述电动马达还包括耦合至所述定子芯的第一端的夹持环和耦合至所述夹持环的计量环，所述计量环适于引导冷却流体流入所述定子芯中，以从所述绕组中去除因所述电动马达的运行而产生的热量。2. The electric motor of claim 1, further comprising a clamping ring coupled to the first end of the stator core and a metering ring coupled to the clamping ring, the metering ring adapted to A cooling fluid is directed into the stator core to remove heat from the windings due to operation of the electric motor.3.根据权利要求2所述的电动马达，其中，所述计量环限定环形主体，所述环形主体被形成为包括冷却剂通道，以允许冷却流体围绕所述环传输。3. The electric motor of claim 2, wherein the metering ring defines an annular body formed to include coolant passages to allow cooling fluid to pass around the ring.4.根据权利要求3所述的电动马达，其中，所述计量环包括径向围绕所述计量环设置的多个指状件，所述指状件与在所述定子芯中形成的所述通路对准。4. The electric motor of claim 3, wherein the metering ring includes a plurality of fingers disposed radially around the metering ring, the fingers being associated with the fingers formed in the stator core Path alignment.5.根据权利要求4所述的电动马达，其中，多个指状件均包括指状件通道，所述指状件通道流体连接至所述冷却剂通道，以允许来自所述冷却剂通道的流体流入在所述定子芯中形成的所述通路中。5 . The electric motor of claim 4 , wherein each of the plurality of fingers includes a finger channel that is fluidly connected to the coolant channel to allow flow from the coolant channel. 6 . Fluid flows into the passages formed in the stator core.6.根据权利要求5所述的电动马达，其中，所述指状件通道的通道面积变化，以使流入所述定子芯的通路中的冷却流体的体积相等。6. The electric motor of claim 5, wherein the channel areas of the finger channels vary to equalize the volume of cooling fluid flowing into the passages of the stator core.7.根据权利要求4所述的电动马达，所述电动马达还包括耦合至所述定子芯的第二端的排放环，所述排放环适于引导冷却流体流出所述定子芯的通路。7. The electric motor of claim 4, further comprising a drain ring coupled to the second end of the stator core, the drain ring adapted to direct the passage of cooling fluid out of the stator core.8.根据权利要求7所述的电动马达，其中，所述排放环包括径向围绕所述排放环设置的多个排放指状件，所述排放指状件与在所述定子芯中形成的所述通路对准。8 . The electric motor of claim 7 , wherein the discharge ring includes a plurality of discharge fingers disposed radially around the discharge ring, the discharge fingers being associated with the discharge fingers formed in the stator core. 9 . The vias are aligned.9.根据权利要求1所述的电动马达，所述电动马达还包括绕组喷头，所述绕组喷头包括具有出口孔的细长管，所述出口孔适于在所述定子的端部处将冷却流体引导到绕组上。9. The electric motor of claim 1, further comprising a winding showerhead comprising an elongated tube having an outlet hole adapted to cool cooling at the end of the stator The fluid is directed onto the windings.10.根据权利要求1所述的电动马达，其中，所述转子包括中心孔，并且所述电动马达还包括孔喷头，所述孔喷头将冷却流体供应到所述孔以冷却所述转子。10. The electric motor of claim 1, wherein the rotor includes a central bore, and the electric motor further includes an orifice spray head that supplies cooling fluid to the bore to cool the rotor.11.根据权利要求10所述的电动马达，其中，所述转子包括与所述孔喷头相反地设置在所述孔中的唇环，所述唇环适于在油离开所述转子的孔之前保留所述油。11. The electric motor of claim 10, wherein the rotor includes a lip ring disposed in the bore opposite the bore nozzle, the lip ring adapted to precede oil exiting the bore of the rotor The oil is retained.12.用于车桥组件的电动马达，所述电动马达包括：12. An electric motor for an axle assembly, the electric motor comprising:具有定子芯的定子，以及适于在所述定子芯内围绕转子轴线旋转的转子；a stator having a stator core, and a rotor adapted to rotate within said stator core about a rotor axis;与所述转子相关联并围绕所述转子定位的多个磁体，所述磁体适于随着所述转子旋转；a plurality of magnets associated with and positioned about the rotor, the magnets adapted to rotate with the rotor;围绕所述定子芯设置的多个导电绕组，所述绕组沿着大体上平行于所述转子轴线的方向缠绕，并从所述定子芯的第一端和第二端突出；a plurality of conductive windings disposed around the stator core, the windings being wound in a direction substantially parallel to the rotor axis and protruding from the first and second ends of the stator core;所述定子芯被形成为包括多个纵向通路，所述通路径向围绕所述定子芯布置并且适于允许冷却流体流过所述通路，所述通路纵向延伸穿过所述定子芯并且定位于所述绕组之间，以使得由所述绕组产生的热量被传递至所述冷却流体，以从所述绕组中去除热量；以及The stator core is formed to include a plurality of longitudinal passages arranged radially around the stator core and adapted to allow cooling fluid to flow therethrough, the passages extending longitudinally through the stator core and positioned at the stator core. between the windings such that heat generated by the windings is transferred to the cooling fluid to remove heat from the windings; and耦合至所述定子芯的第一端的夹持环和耦合至所述夹持环的计量环，所述计量环适于引导冷却流体流入所述定子芯中，以从所述绕组中去除因所述电动马达的运行而产生的热量。A clamping ring coupled to the first end of the stator core and a metering ring coupled to the clamping ring, the metering ring adapted to direct cooling fluid into the stator core to remove the cause from the windings heat generated by the operation of the electric motor.13.根据权利要求12所述的电动马达，其中，所述计量环限定环形主体，所述环形主体被形成为包括冷却剂通道，以允许冷却流体围绕所述环传输。13. The electric motor of claim 12, wherein the metering ring defines an annular body formed to include coolant passages to allow cooling fluid to pass around the ring.14.根据权利要求13所述的电动马达，其中，所述计量环包括径向围绕所述计量环设置的多个指状件，所述指状件与在所述定子芯中形成的所述通路对准。14. The electric motor of claim 13, wherein the metering ring includes a plurality of fingers disposed radially around the metering ring, the fingers being associated with the fingers formed in the stator core Path alignment.15.根据权利要求14所述的电动马达，其中，多个指状件均包括指状件通道，所述指状件通道流体连接至所述冷却剂通道，以允许来自所述冷却剂通道的流体流入在所述定子芯中形成的所述通路中。15. The electric motor of claim 14, wherein each of the plurality of fingers includes a finger channel that is fluidly connected to the coolant channel to allow flow from the coolant channel Fluid flows into the passages formed in the stator core.16.根据权利要求15所述的电动马达，其中，所述指状件通道的通道面积变化，以使流入所述定子芯的通路中的冷却流体的体积相等。16. The electric motor of claim 15, wherein the channel areas of the finger channels vary to equalize the volume of cooling fluid flowing into the passages of the stator core.17.根据权利要求14所述的电动马达，所述电动马达还包括耦合至所述定子芯的第二端的排放环，所述排放环适于引导冷却流体流出所述定子芯的通路。17. The electric motor of claim 14, further comprising a drain ring coupled to the second end of the stator core, the drain ring adapted to direct the passage of cooling fluid out of the stator core.18.根据权利要求17所述的电动马达，其中，所述排放环包括径向围绕所述排放环设置的多个排放指状件，所述排放指状件与在所述定子芯中形成的所述通路对准。18. The electric motor of claim 17, wherein the discharge ring includes a plurality of discharge fingers disposed radially around the discharge ring, the discharge fingers associated with the discharge fingers formed in the stator core The vias are aligned.19.根据权利要求12所述的电动马达，所述电动马达还包括绕组喷头，所述绕组喷头包括具有出口孔的细长管，所述出口孔适于在所述定子的端部处将冷却流体引导到绕组上。19. The electric motor of claim 12, further comprising a winding showerhead comprising an elongated tube having outlet holes adapted to cool cooling at the ends of the stator The fluid is directed onto the windings.20.用于车桥组件的电动马达，所述电动马达包括：20. An electric motor for an axle assembly, the electric motor comprising:具有定子芯的定子，以及适于在所述定子芯内围绕转子轴线旋转的转子；a stator having a stator core, and a rotor adapted to rotate within said stator core about a rotor axis;与所述转子相关联并围绕所述转子定位的多个磁体，所述磁体适于随着所述转子旋转；a plurality of magnets associated with and positioned about the rotor, the magnets adapted to rotate with the rotor;围绕所述定子芯设置的多个导电绕组，所述绕组沿着大体上平行于所述转子轴线的方向缠绕，并从所述定子芯的第一端和第二端突出；以及a plurality of conductive windings disposed around the stator core, the windings being wound in a direction substantially parallel to the rotor axis and protruding from first and second ends of the stator core; and所述定子芯被形成为包括多个纵向通路，所述通路径向围绕所述定子芯布置并且适于允许冷却流体流过所述通路，所述通路纵向延伸穿过所述定子芯并且定位于所述绕组之间，以使得由所述绕组产生的热量被传递至所述冷却流体，以从所述绕组中去除热量；The stator core is formed to include a plurality of longitudinal passages arranged radially around the stator core and adapted to allow cooling fluid to flow therethrough, the passages extending longitudinally through the stator core and positioned at the stator core. between the windings such that heat generated by the windings is transferred to the cooling fluid to remove heat from the windings;耦合至所述定子芯的第一端的计量环和耦合至所述定子芯的第二端的排放环，所述环适于引导冷却流体流过所述定子芯的通路，以从所述绕组中去除因所述电动马达的运行而产生的热量。A metering ring coupled to a first end of the stator core and a drain ring coupled to a second end of the stator core, the rings adapted to direct cooling fluid flow through the passages of the stator core to drain from the windings Heat generated by the operation of the electric motor is removed.

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